LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 

GIFT  OF" 


} 


STATE.  HORTICULTURAL  COMMISSION 

ELLWOOD  COOPER,  Commissioner 


BUG  V5.  BUG 

Nature's  Method  of  Controlling 
Injurious  Species 


BY 

JOHN  I5AAC 


Reprinted  from  the  First  Biennial  Report  of  the 
State  Horticultural  Commissioner. 


W.  W.  SHANNON, 


SACRA  MLNTO 


1906 


SUPT.  STATE.  PRINTING 


CALIFORNIA  STATE  COMMISSION  OF  HORTICULTURE.. 


ELLWOOD  COOPER Commissioner Santa  Barbara 

JOHN  ISAAC Secretary San  Francisco 

ED.  M.  EHRHORN Deputy Mountain  View 

E.  K.  CARNES Assistant...          .Riverside 

O.  E.  BREMNER    Assistant ._ Santa  Rosa 

CHAS.  T.  PAINE. ...         .Assistant ..Redlands 

GERTRUDE  BIRD Stenographer Sacramento 


OFFICE: 

ROOM  41,  STATE  CAPITOL,  SACRAMENTO. 
BRANCH  OFFICE,  ROOM  11,  FERRY  BUILDING,  SAN  FRANCISCO. 


„.   THE 

UNIVERSITY 

OF 


BUG  VS.  BUG. 

BY  JOHN  ISAAC. 


A  somewhat  small  aucl  unpretentious  exhibit  was  that  made  at  the 
St.  Louis  Exposition  by  the  California  State  Commissioner  of  Horti- 
culture, but  it  was  one  that  attracted  a  great  deal  of  attention,  especially 
among  scientific  men  and  the  more  intelligent  class  of  orchardists  and 
farmers  who  visited  that  great  exposition.  This  exhibit  consisted  of  a 
very  complete  and  well-arranged  collection  of  the  various  insect  friends 
to  which  California  owes  so  much  of  her  prosperity,  and  which  are  ever 
and  continuously  working  in  our  interest.  Many  of  these  insects  are 
exceedingly  minute,  so  much  so  as  to  be  practically  out  of  the  range  of 
the  naked  eye.  To  overcome  this  difficulty  they  were  displayed  behind 
magnifying  glasses  of  sufficient  power  to  enable  them  to  be  seen,  while 
descriptions  of  them  and  the  work  they  are  doing  for  our  State  were 
made  in  plain  language.  The  result  of  this  has  been  a  great  deal  of 
inquiry  from  Eastern  sources  as  to  our  beneficial  insects  and  our  Cali- 
fornia method  of  fighting  bugs  with  bugs.  To  answer  these  inquiries, 
as  well  as  to  give  our  own  people  a  wider  knowledge  of  what  our  insect 
friends  are  doing  for  us,  the  following  pages  have  been  prepared. 

Bfelow  is  a  list  of  the  different  insects  exhibited  at  the  St.  Louis 
Exposition  by  this  Commission: 

PREDACEOUS  COCCINELLIDyE. 

Beneficial  Insects.  ITost  Insects. 

Vedalia  cardinalis  Cottony  Cushion  Scale  (Icerya  purchasi). 

Novius  koebelei Cottony  Cushion  Scale  (Icerya  purchasi). 

Novius  bellus Cottony  Cushion  Scale  (Tcerya  purchasi). 

Vedalia  sp.  (black). Cottony  Cushion  Scale  (Icerya  purchasi). 

Rhizobius  ventralis ..Black  Scale  (Saisseta  oleoe). 

Rhizobius  ventralis,  larvae-  _. Black  Scale  (Saisseta  olese). 

Orcus  australasia Black  Scale  (Saisseta  oleoe). 

Orcus  chalybeus Yellow  Scale  (Chrysomphalus  [Aspidiotus]  citrinus). 

Rhizobius  toowoombte.   ...     San  Jose"  Scale  (Aspidiotus  perniciosus). 

Scymnus  vagaiis Red  Spider  (Tetranychus  telarius). 

Rhizobius  debilis ...  Various  scale  insects. 

Cryptolsemus  montrouzieri ._ Mealy  Bugs  (Pseudococcus  [Dactylopius]  sp.). 

Hyperaspis  lateralis 1 Cypress  Mealy  Bugs  (Pseudococcus  ryani). 

Exochomus  pilatii Various  scale  insects. 

Chilocorus  bivulnerus.-.   San  Jos6  Scale  (Aspidiotus  perniciosus),  and  others. 

Coccinella  sanguinea Various  scales  and  aphids. 

Coccinella  calif ornica Various  aphids. 

Coccinellu  abdominalis ..Various  aphids. 

Coccinella  oculata Various  aphids. 

Hippodamia  ambigua Various  aphids. 

Hippodamia  convergens Various  aphids. 

04 


4  CALIFORNIA   STATE    HORTICULTURAL    COMMISSION. 

PARASITIC  HYMENOPTERA,  DIPTERA,  ETC. 

Beneficial  Insects.  Host  Insects, 

Scutellista  cyanea Black  Scale  (Saisseta  olese). 

Dilophogaster  californica Black  Scale  (Saisseta  olese). 

Hymencyrtus  crawii ...  Black  Scale  (Saisseta  olese). 

Aphelinus  mytilaspidis Black  Scale  (Saisseta  olese). 

Aphelinus  fuscipennis San  Jose"  Scale  (Aspidiotus  perniciosus). 

Aspidiotophagus  citrinus Yellow  Scale  (Chrysomphalus  [Aspidiotus]  citriiius)  and 

San  Jose"  Scale  (Aspidiotus  perniciosus). 

Pteroraalus  puparum Internal  parasite  of  the  Cabbage  Butterfly  (Pieris  rapse). 

Gorays  fusca Brown  Apricot  Scale  (Eulecanium  armeniacum). 

Encyrtus  flavus Soft  Brown  Scale  (Lecanium  [CoccusJ  hesperidum). 

Coccophagus  lecani Soft  Brown  Scale  (Lecanium  [Coccus]  hesperidum). 

Coccophoctonus  sp Yellow  and  Red  scales. 

Eupelmus  mirabilis Internal  parasite  of  the  Katydid  (Microceiitrumretinervis). 

Braconidsp Parasite  of  Cutworm. 

Anastatus  sp - Egg  parasite  of  Tent  Caterpillar. 

Tachnia  fly Internal  parasite  of  Cabbage  Butterfly  (Pieris  rapte). 

_ Internal  parasite  of  Lecanium  robinarum. 

Aphelinus  sp. Internal  parasite  of  Aphis. 

Somewhere  about  the  year  1868,  a  California  nurseryman  in  San 
Mateo  County,  not  far  from  San  Francisco,  imported  some  lemon  trees 
from  Australia.    There  was  nothing  unusual  about  this,  nor  was  there 
apparently   anything   unusual  on  the   trees   themselves;   nevertheless 
that  importation  cost  the  State  of  California  millions  of  dollars  and 
came  near  destroying  one  of  the  most  important  of  its  fruit  industries, 
for  on  those  trees,  unseen  and  unnoticed  by  any  one,  were  some  of  the 
young  of  the  now  well-known  cottony  cushion  scale  (Icerya  purchasi) . 
These  soon  reached  their  mature  stage,  and  still  no  notice  was  taken  of 
them;  they  were  regarded  merely  as  a  curious  object  when  noticed,  and 
it  was  never  dreamed  that  they  were  the  commencement  of  one  of  the 
most  terrible  pests  that  California  fruit-growers  have  ever  known.    The 
insects  increased  in  numbers,  but  not  being  in  a  fruit  section,  and  their 
depredations  being  confined  largely  to  ornamental  stuff,  they  were  dis- 
regarded.     Soon   afterwards   a  Los   Angeles   nurseryman    and   florist 
secured  some  of  the  imported  stock,  with  the  imported  pest,  and  so  it 
was  introduced  into  Southern  California.    Here  conditions  were  better 
suited  to  it  than  even  in  the  section  where  it  had  first  obtained  a  foot- 
ing in  the  State,  and  it  spread  much  more  rapidly.     Soon  it  got  into 
the  orange  orchards.     Here  conditions  seemed  perfect,  and  in  a  very 
short  time  it  had  spread  to  an  alarming  extent.     Orchards  in  which  it 
had  become  firmly  established  were  covered  with  it  until  they  looked 
as  though  they  had  been  exposed  to  a  severe  snowstorm.     It  was  soon 
found  in  remote  sections,  and  in  a  short  time  appeared  to  have  taken 
possession  of  the  whole  country.    Nor  did  it  confine  itself  to  the  orange 
trees;   many  varieties  of  fruit   and   a  great  quantity  of  ornamental 
plants  fell  beneath  its  attacks.     It  even  found  its  way  to  forest  trees, 
and  for  some  time  it  looked  as  though  it  would  reduce  the  whole  country 


BUG    VS.    BUG.  O 

to  a  desert.  Orange-growers  were  in  despair.  From  eight  thousand 
carloads,  shipments  dropped  to  six  hundred  in  one  year.  Every  pos- 
sible remedy  was  tried,  but  none  was  found  effective,  and  even  the  most 
costly  served  only  to  temporarily  check  the  spread  of  the  pest.  Orange- 
growers  were  digging  out  and  burning  their  trees  to  get  rid  of  the  pest, 
but  even  this  did  not  avail,  for  had  all  the  orhards  been  destroyed  there 
was  sufficient  wild  stuff  to  keep  it  spreading. 

In  1888  the  National  Government  made  an  appropriation  for  the 
purpose  of  advancing  the  American  interests  at  the  Melbourne  Expo- 
sition, and  the  appointment  of  the  late  Hon.  Frank  McCoppin  as 
chairman  of  the  commission  to  forward  said  interests  was  the  nucleus 
of  California's  first  effort  in  the  search  for  natural  enemies  of  orchard 
pests.  McCoppin 's  friends  in  the  orange  district  where  this  pest  had 
caused  such  terrible  losses  urged  that  he  should  do  something  to  save 
the  orange  industry.  Correspondence  was  opened  with  the  Hon. 
Thomas  F.  Bayard,  Secretary  of  State,  and  through  him,  with  the 
Department  of  Agriculture  and  the  Entomological  Division  of  that 
Department.  This  resulted  in  the  sending  of  Albert  Koebele,  who  dis- 
covered the  Vedalia  cardinalis,  with  the  commission.  While  there  were 
„  others  in  the  State  who  were  convinced  of  the  parasitic  theory  and 
enthusiastic  in  their  efforts  to  bring  about  the  investigation,  there  was  no 
available  money  until  the  above  opportunity  presented  itself. 

This  discovery  of  a  small  ladybird  known  as  the  Vedalia  cardinalis 
started  California  on  her  present  course  of  fighting  bugs  with  bugs,  and 
no  doubt  this  will  continue  until  every  insect  pest  that  disturbs  plant 
life  and  its  fruits  will  be  overcome  by  natural  insect  enemies,  even  if  it 
should  require  traversing  the  very  ends  of  the  earth. 

It  is  to  be  hoped  that  other  states,  and  the  National  Government,  will 
take  up  this  work  and  thereby  save  hundreds  of  millions  of  dollars'  loss 
that  is  now  borne  by  the  cultivators  of  the  soil. 

This  ladybird  was  collected  and  forwarded  to  California  and  dis- 
tributed all  over  the  State  wherever  the  scale  had  made  its  appearance. 

Nearly,  if  not  quite,  all  of  the  injurious  pests  of  any  section  are  intro- 
duced species,  and  in  every  case  they  have  been  introduced  without  their 
checks,  for  in  its  native  habitat  every  pest,  in  fact  every  form  of  life, 
has  some  other  form  of  life  which  preys  upon  it  and  prevents  it  from 
becoming  redundant.  Now,  when  any  such  form  is  removed  to  a  new 
section,  where  it  has  no  natural  enemies,  there  is  nothing  to  stop  its 
unlimited  spread,  and  as  insects  propagate  more  rapidly  than  any 
other  form  of  animal  life,  without  some  check  they  would 'soon  overrun 
everything  within  reach.  These  checks  are  usually  other  insects,  and 
they  are  divided  into  two  general  classes— the  predaceous  class,  or  those 
which  devour  their  prey  from  the  outside,  the  most  important  among 
which  is  the  great  ladybird  family,  and  the  parasitic  class,  or  those  which 


6  CALIFORNIA   STATE   HORTICULTURAL    COMMISSION. 

work  in  or  on  the  body  of  their  host.  These  latter  are  often  microscopic, 
or  very  nearly  microscopic,  in  size,  but  are  among  the  most  effective  of 
our  insect  friends. 

Usually  each  predaceous  or  parasitic  insect  attacks  but  one  kind  of 
insect ;  each  has  its  own  particular  form  of  food  and  will  touch  no  other. 
The  Vedalia,  for  instance,  lives  wholly  upon  the  cottony  cushion  scale, 
and  if  it  can  not  get  this,  it  will  starve  before  it  will  touch  any  other 
form  of  food;  so  that,  in  searching  for  the  enemies  of  onr  destructive 
insects,  it  is  necessary  to  find  just  the  right  one. 

It  is  a  fact  well  known  to  all  entomologists,  that  in  their  native  homes, 
while  insects  are  sometimes  very  troublesome,  and  in  some  sections  exist 
in  unusual  numbers,  they  never  become  the  serious  pests  that  they  do 
when  they  are  removed  to  a  new  country  where  their  checks  do  not  exist. 
Usually  in  their  native  homes  they  are  rather  rare  than  otherwise.  So 
when  it  is  known  that  any  pest  is  especially  severe  in  any  section,  as,  for 
instance,  the  San  Jose  scale  (Aspidiotus  perniciosus)  over  a  great  part 
of  the  Eastern  States,  it  is  very  certain  that  it  has  been  introduced  there, 
and  in  order  to  find  its  check,  we  must  find  its  native  home,  where  it  is 
scarce,  and  then  we  must  find  what  agency  is  keeping  it  down.  Some- 
times our  native  parasites  will  adapt  themselves  to  the  introduced 
species,  as  has  been  the  case  in  California  with  the  San  Jose  scale.  This 
pest  was  as  great  a  terror  to  our  growers  some  twenty  years  ago  as  it  now 
is  over  a  great  part  of  the  Eastern  States ;  but  one  of  our  native  parasites, 
the  Aphelinus  fuscipennis,  adapted  its  taste  to  it,  and  finding  in  the  San 
Jose  scale  a  suitable  food  supply,  it  increased  with  almost  unprecedented 
rapidity  until  it  overtook  the  scale,  and  to-day  this  scale  is  no  longer  a 
pest  in  the  California  orchards.  It  is  true  that  it  occasionally  makes  its 
appearance  in  remote  sections,  but  never  to  any  dangerous  extent,  and 
the  little  parasite  soon  overtakes  it  and  reduces  it  below  the  danger  line. 
So  little  regard  is  paid  to  the  San  Jose  scale  in  California  now,  that  we 
never  recommend  any  action  against  it.  Spraying  is  still  carried  on, 
but  this  is  more  for  the  purpose  of  keeping  the  trees  clean  and  healthy 
'than  for  the  purpose  of  getting  rid  of  the  San  Jose  scale.  Before  this 
parasite  did  such  effective  work,  California  orchardists  were  having  very 
much  the  same  experience  that  their  Eastern  brethren  are  having  now, 
and  trees  by  thousands  were  dug  out  and  destroyed  in  order  to  get  rid 
of  the  scale.  It  is  to  be  hoped  that  the  days  of  this  terrible  pest  in  the 
Eastern  orchards  are  numbered,  for  it  has  been  discovered  that  the  same 
parasite  which  has  freed  the  California  orchards  is  now  at  work  there, 
and  in  a  report  made  by  Prof.  W.  G.  Johnson,  when  entomologist  of 
Maryland,  he  says: 

Since  we  assumed  charge  of  the  State  work  in  Maryland,  we  have  collected  the  S:m 
JosA 'scale  on  various  food  plants  and  inclosed  infested  twigs,  about  four  inches  in 
length,  in  glass  cylinder  tubes,  open  at  both  ends  ;  the  ends  were  closed  with  cotton,  and 
if  any  parasites  existed  upon  the  scale,  they  were  easily  detected  and  mounted  for 


BUG   VS.   BUG.  7 

study.  Only  upon  rare  occasions  have  we  taken  more  than  a  half-dozen  specimens 
from  a  single  tube.  This  experience  has  been  repeated  year  after  year  until  the  fall 
of  1899.  *  *  *  Last  fall,  however,  I  discovered  a  new  locality  for  Aphelinus 
fuscipcnms,  near  Easton,  Talbot  County,  in  an  infested  orchard  along  the  Miles 
River.  The  orchard  contained  a  miscellaneous  variety  of  fruits,  and  all  the  trees 
were  quite  seriously  infested  with  ,tfee  San  Jose  scale.  Instructions  have  been  given 
the  owner  to  cut  them  down  as  soon  as  possible  and  burn  them.  A  quantity  of  small 
branches  infested  with  scale  were  brought  to  the  laboratory  and  inclosed  in  breeding 
tubes.  Much  to  my  surprise,  these  tubes  were  swarming  with  parasites  a  few  days 
later.  Prom  one  tube  3,114  specimens  of  ApheUnufi  fuscipennis  were  taken,  while 
a  second  tube  gave  432,  a  third  1,478,  and  a  fourth  more  than  1,000,  but  owing  to 
an  accident  the  count  in  the  case  last  mentioned  was  not  exact. 

The  California  method  of  fighting  insect  pests  is  to  use  the  most 
efficient  artificial  means  while  we  have  to,  and  to  this  end  we  apply  all 
sorts  of  known  washes,  dips,  and  fumigation,  but,  while  so  doing,  we 
realize  that  these  measures  are  very  cumbersome,  costly  and  inefficient, 
and  that  nature  has  provided  a  better  way,  and  it  is  of  this  way  that  we 
avail  ourselves.  We  endeavor  to  trace  back  the  course  traveled  over  by 
our  destructive  pests,  to  trail  them  to  their  native  lair,  and  there  we 
will  find  their  check.  This  check,  whether  it  be  a  parasitic  or  a  preda- 
ceous  insect,  or  both,  as  sometimes  found,  we  secure,  introduce,  and 
breed,  with  the  greatest  care,  in  our  insectary,  where  it  becomes  accli- 
mated in  its  new  home,  and  as  it  propagates  it  is  sent  into  those  sections 
where  the  pest  upon  which  it  is  to  prey  is  most  prevalent.  This  method 
has  been  found  so  effective  that  we  have  now  very  few -really  trouble- 
some orchard  pests,  the  worst  at  the  present  time  being  the  codling- 
moth,  and  for  this  we  hope  to  find  a  natural  check,  and  are  now  working 
toward  that  end. 

It  must  not  be  supposed  from  this  that  there  are  no  insect  pests  in 
California.  We  have  been  importing  these  pests  from  all  parts  of  the 
world  for  half  a  century  past  and  have  had  representatives  from  all 
parts  of  the  world,  and  have  them  still,  for  when  an  insect  once  obtains  a 
foothold,  its  eradication  is  practically  impossible,  but  by  introducing  its 
natural  enemy,  we  offset  one  against  the  other,  and  give  ourselves  no 
further  uneasiness  as  to  the  outcome.  The  pests  may  do  some  damage, 
they  may  break  out  in  sections  in  unusual  numbers  for  a  time,  but 
invariably  they  are  reduced  below  the  line  of  serious  damage  shortly 
by  the  natural  means,  and  it  is  done  more  effectively  and  permanently 
than  can  be  done  by  any  artificial  method. 

In  an  address  before  the  fourteenth  annual  meeting  of  the  Association 
of  Economic  Entomologists,  Prof.  C.  L.  Marlatt  gave  an  account  of  a  trip 
he  had  made  to  Japan  and  China  in  search  of  the  native  home  of  the 
San  Jose  scale,  and  in  speaking" of  its  discovery  there  he  alluded  to  para- 
sites which  he  found  working  upon  it,  and  which  are  the  same  species 
which  have  done  such  good  work  on  this  pest  in  California.  He  said: 

The  apple  industry  of  Japan  is  of  recent  origin,  say  within  the  last  thirty  years ; 
most  of  the  stock  has  been  obtained  from  California,  and  as  a  rule  was  more  or  less 


EXPLANATION  OF  PLATE  I. 

Fig.  1.     Novius  koebelei,  Olliff ;    Koebele's  ladybird.     Male;    enlarged, 
la.  Novius  koebelei.     Male ;  natural  size. 
1&.  Novius  koebelei.     Female;  natural  size. 
Ic.  Novius  koebelei.     Larva ;  enlarged. 

2.  "Black  Vedalia."     Enlarged. 

3.  Novius  bellus.    Beautiful  ladybird;  enlarged. 

4.  Novius   (Vedalia)    cardinalis,  Mulsant;  Australian   ladybird; 
4a.  Novius  (Vedalia)  cardinalis.    Natural  size. 

4&.  Novius  (Vedalia)  cardinalis.    Larva ;  enlarged. 

5.  Lestophonus  icerya.    Dipterous  parasite  of  the  cottony  cushion 

scale;  enlarged. 
5a.  Lestophonus  icerya.     Natural  size. 

6.  Ophilosia  crawfordi.     Hymenopterous  parasite  of  the  cottony 

cushion  scale;  enlarged. 
6a.  Ophilosia  crawfordi.     Natural  size. 

7.  Twig  infested  with  cottony  cushion  scale ;  natural  size. 
la.  Icerya  purchasi  crawii,  Cockerell. 

7b.  Icerya  purchasi  inaskelli. 


CALIFORNIA  STATE  COMMISSION 
OF   HORTICULTURE. 


PLATE 


BUG    VS    BUG. 


THE     BENEFICIAL     IPi 

THAT    SAVED     THE 
CITRUS     FRUIT     INDUSTRY"  OF    CALIFORNIA. 


BUG    VS.    BUG. 

infested  with  San  Jose  scale  when  received.  Throughout  this  region  the  San  Jos6 
scale  was  found  scatteringly  in  all  orchards  and  in  all  gardens.  In  Aomori  and 
vicinity  it  is  doing  no  very  great  damage  in  any  of  the  orchards,  but  in  some  of  the 
small  gardens  and  especially  in  one  or  two  neglected  ones  in  the  city  of  Aomori,  it 
was  as  abundant  on  particular  trees  as  it  often  is  in  America.  At  the  first  investi- 
gation no  evidence  of  parasitism  was  seen,  but  from  later  collections  two  of  the 
parasites  which  attack  the  scale  insect  in  America  were  raised  in  great  numbers  from 
infested  branches  collected  at  Aomori.  These  as  determined  by  Dr.  Howard  are 
Aphelinux  fuscipennis,  How.,  and  Aspidiotophagus  citrinus,  Craw,  the  latter  being 
the  more  numerous. 

This  latter  parasite  is  the  true  internal  parasite  of  the  Japanese 
yellow  orange  scale.  The  San  Jose  scale  is  not  a  native  of  Japan,  so  it 
is  evident  that  this  little  parasite  adapts  itself  to  the  introduced  variety, 
which  is  a  near  relative  of  the  yellow  scale  upon  which  it  is  generally 
found. 

So  effective  has  this  work  of  introducing  beneficial  insects  and  encour- 
aging native  parasites  been,  that  we  have  practically  reduced  all  the 
worst  of  our  scale  pests  and  very  many  other  destructive  insects  below 
the  danger  line.  Among  the  many  beneficial  insects  which  are  now  at 
work  in  our  State,  and  the  pests  which  they  are  at  work  upon,  and  most 
of  which  they  keep  in  control,  we  name  the  following : 

COCClNELLIDjE. 

Vedalia  eardinalis,  Mulsant.  (Plate  I,  Figs.  4,  4r/,  4/>.)  This  is 
commonly  known  as  the  "Australian  ladybird,"  from  the  fact  that  it 
was  imported  from  Australia  in  order  to  work  upon  the  cottony  cushion 
scale  (Icerya  purchasi,  Maskell).  As  stated  above,  this  pest  had 
obtained  such  a  foothold  in  our  orange  orchards  that  the  citrus  industry 
of  California  was  threatened.  The  fact  that  the  cottony  cushion  scale 
came  from  Australia,  where  it  was  not  a  pest,  was  sufficient  proof  that 
there  was  some  very  efficient  check  at  Avork  upon  it  there,  and  investiga- 
tion by  Albert  Koebele  discovered  this  little  beetle.  The  ora.nge-growers 
of  Los  Angeles  County,  especially,  had  a  very  expensive  experience  with 
this  scale.  As  it  had  spread  into  the  wild  bushes  and  trees,  extermina- 
tion by  artificial  means  was  out  of  the  question.  Now  the  scale  is  no 
longer  a  pest.  When  it  appears  in  an  orchard  the  owner  is  supplied 
with  a  colony  of  Vedalia.  During  the  summer  the  transformations  of 
this  iadybird  are  very  rapid.  From  the  egg,  through  the  larva  and 
chrysalis,  to  the  perfect  beetle,  takes  only  twenty-one  days.  Of  course, 
the  larvae  are  the  most  active  feeders.  When  short  of  feed,  the  larvae 
will  attack  each  other,  but  no  matter  how  hungry  they  are  they  will  not 
eat  any  other  species  than  the  cottony  cushion  scale.  This  ladybird 
breeds  throughout  the  year. 

Novius  koebelei,  Olliff   (Koebele's  ladybird).     (Plate  I,  Figs.  1,- la, 
16,  Ic.)     This  is  another  effective  enemy  of  the  cottony  cushion  scale 
2 — BII 


10  CALIFORNIA    STATE   HORTICULTURAL    COMMISSION. 

and  does  as  good  work  as  the  Vedalia.  The  latter,  however,  was  first 
introduced,  and  its  reputation  became  so  great  that  all  others  were  over- 
shadowed by  it.  The  Novius  koebelei,  however,  has  proved  itself  equally 
as  prolific  and  quite  as  voracious  a  devourer  of  the  cottony  cushion 
scale  as  its  companion.  This  ladybird  is  also  an  introduced  species, 
having  been  sent  from  Australia  for  the  State  Board  of  Horticulture 
by  Mr.  Koebele  ori  his  second  trip  to  that  country. 

The  illustrations  give  a  good  idea  of  this  beautiful  and  active  little 
ladybird.  It  feeds  upon  the  cottony  cushion  scale  (leery a  purcJtasi), 
searching  out  the  solitary  scales  even  better  than  the  Vedalia.  It  passes 
through  its  different  stages  in  about  the  same  time  as  the  latter. 


FIG.  1.    Xovius  koebelei,  male,  enlarged.  FIG.  2.     Novius  koebelei,  female,  enlarged. 


Novius  bellus  (Beautiful  ladybird).  (Plate  I,  Fig.  3.)  This  is  also 
an  Australian  species,  having  been  introduced  into  California  from  that 
country  by  Mr.  George  Compere.  It  is  one  of  the  several  coccinellid 
enemies  of  the  cottony  cushion  scale,  and  has  done  very  excellent  work 
upon  that  pest.  It  has  been  generally  distributed  over  the  State. 

Vedalia  sp.  (Plate  I,  Fig.  2.)  This  is  an  unnamed  species  of  Veda  Ha. 
from  its  color  commonly  known  as  the  "Black  Vedalia."  It  is  also  an 
Australian  species,  introduced  by  the  State  Board  of  Horticulture 
through  Mr.  George  Compere,  and  is  another  of  the  coccinellids  which 
prey  upon  the  cottony  cushion  scale. 

Rhizobius  ventralis  (Black  ladybird).  (Plate  IV,  Figs.  3,  3o,  ?,b.) 
This  is  also  an  Australian  ladybird,  introduced  by  the  State  Board  of 
Horticulture  through  Mr.  Koebele,  and  is  one  of  the  natural  enemies  of 
the  black  scale  (Saisseta  [Lecanium]  oleae) .  This  ladybird  was  intro- 
duced for  work  on  the  black  scale,  and  was  generally  distributed  by 
the  State  Board  of  Horticulture  wherever  that  pest  was  found.  It  was 
one  of  the  most  promising  of  the  many  importations  of  beneficial  insects 
and  took  hold  of  its  work  with  a  vigor  that  gave  promise  of  soon  extir- 
pating one  of  the  worst  of  the  California  scale  insects.  Wherever  it  was 
introduced  in  the  coast  counties  of  the  State,  it  increased  with  wonderful 


BUG   VS.    BUG. 


11 


rapidity  and  the  scale  as  rapidly  disappeared,  and  in  those  sections  it 
still  continues  to  do  good  work,  but  efforts  to  establish  it  in  the  interior 
counties  have  not  met  with  as  good  success,  the  heat  probably  being  too 
intense  for  the  young  larva?.  This  insect,  however,  is  well  established 
all  over  the  State,  and  in  many  sections  is  as  abundant  as  any  of  our 
native  species.  Wherever  it  is  abundant,  it  is  a  chief  factor  in  keeping 
in  check  the  destructive  black  scale. 

Oreus  australasia,  Boisd.    (Six-spotted   blue   ladybird).      (Fig.  3.) 
This  is  one  of  the  most  beautiful  of  the  introduced  species.    Like  most 


OHCUS  AUSTRALASIA.  Boisd  'magnified!;  la.  Ditto-natural  i 
£  Pupa  enveloped  in  larval  skin;  2a.  Ditto  (natural  i 
3  I.arva:  3a.  Ditto  (natural  sizei. 


FIG.  3.    Oreus  australasia. 

of  the  latter,  it  is  a  native  of  Australia,  and  was  imported  from  that 
country  by  the  State  Board  of  Horticulture  through  Mr.  Koebele.  It  is 
an  enemy  of  the  black  scale  (Saisseta  [Lecanium]  oleae) ,  and  is  now 
well  established  in  many  parts  of  California,  especially  in  the  coast 
counties.  The  female  is  nearly  one  fourth  of  an  inch  in  length,  deep 
blue  in  color,  with  six  orange  red  spots  on  the  wing-covers.  The  male 
is  similarly  marked,  but  is  a  smaller  insect.  This  species  is  a  more 
general  feeder  than  0.  chalybeus.  In  Santa  Barbara  w 

•tflkMt   ..* 

County  it  is  bred  on  black  scale,  and  in  Alameda  on  the 
pernicious  scale.  It  loves  the  sunshine,  and  is  found 
more  numerous  toward  the  top  and  the  outside  branches 
of  the  trees  in  which  it  is  established.  The  larva  and 
pupa  resemble  the  same  stages  of  Pilate's  ladybird. 

Oreus  ehalybeus,  Boisd.   (Steel-blue  ladybird).     (Fig. 
4.)     So  named  from  its  brilliant  steel-blue  color,  which 
makes  it  a  conspicuous  object  wherever  it  is  found.    This 
ladybird 'preys  largely  upon  the  yellow  scale  (Clirysom- 
plialus [Aspidiotus]  citrinus,  Coquillett),  and  also  upon    beus,  enlarge!*  * 
the  red  scale   (Clirysomplialus   [Aspidiotus]   aurantii,  Maskell),  which 
it  consumes  in  great  quantities.     This  was  introduced  into  California 


EXPLANATION  OF  PLATE  II. 

Fig.  1.     Encyrtus  flavus,  Howard.     Enlarged, 
la.  Encyrtus  flavus.     Natural  size. 

2.  Coccophagus  lecani,  Howard.     Enlarged. 
2a.  Coccophagus  lecani.     Natural  size. 

3.  Comys  fusca,  Howard.     Enlarged. 
3a.  Comys  fusca.     Natural  size. 

4.  Soft   brown   scale    (Coccus    [Lecanium]    liesperidum,   Linn.). 

On  orange  leaf. 

5.  Brown   apricot  scale    (Eulecanium    [Lecanium]    armeniacuw, 

Craw).     On  prune  twig. 

6.  Brown  apricot  scale,  showing  exit  holes  of  Comys  fusca. 


CALIFORNIA  STATE  COMMISSION 
OF   HORTICULTURE. 


PLATE  II 


BUG    VS    BUG. 

THE  INTERT1AL,  PARASITES   THAT  HOLD  I  IN!  CHECK 

THE  "SOFT  BR.OWM  SCALE"  AND  THE 
"BROWN  APRICOT  SCALE"  IN  CAI.IFORMIA 


CALIPO? 


Bl'G    V£ 

by  the  State  Board  of  Horticulture  some  years  ago  and  is  now  found 
established  in  many  parts  of  the  State. 

Rhizobius  (toowoombse)  lopantha.  (Plate  III,  Fig.  (>.)  This  little 
ladybird  was  formerly  described  under  the  name  of  Scymnus  margini- 
collis,  but  is  identical  with  Rhizobius  lopantha.  Mr.  Koebele  sent  this 
beetle  about  the  same  time  that  he  introduced  the  Vedalia,  but  it  was 
found  in  the  State  previous  to  that.  However,  it  has  only  been  within 
the  past  few  years  that  its  value  has  been  observed.  It  breeds  from 
early  spring  until  late  in  the  fall.  As  compared  with  the  beetles  the 
larvae  are  very  large,  they  are  light  colored,  with  a  lighter  oblong  square 
on  center  of  the  back,  and  remain  a  long  time  in  the  larval  stage,  feed- 
ing voraciously.  When  about  to  change  to  the  chrysalis,  they  hide 
away  under  cobwebs,  dry  leaves,  and  other  debris.  The  beetle  is 
metallic  black,  with  a  brown  thorax.  They  feed  on  Aspidiotus  perni- 
ciosus,  Chrysomphalus  (Aspidiotus)  aurantii,  Chrysomphalus  (Aspidio- 
tus) citrinus.  Aspidiotus  hederae  (nerii),  and  occasionally  on  aphis. 
In  San  Diego  County  it  is  proving  effective  on  purple  scale  (Lepidosa- 
phes  beckii) .  In  alluding  to  the  excellent  work  of  this  little  beetle  on 
the  purple  scale  in  the  above  named  county,  Mr.  Allen,  of  Bonita. 
writes : 

With  us  the  largest  hatch  of  purple  scale  has  usually  been  in  May.  So  far  this 
year  I  have  not  seen  a  single  instance  of  purple  scale  hatching,  nor  can  I  find  any 
live  scale  in  an  orchard  adjoining  us,  every  tree  of  which  a  year  ago  was  literally 
alive  with  them.  Since  last  July  this  orchard  has  been  to  iny  knowledge  thoroughly 
stocked  with  the  Scymnus,  though  when  they  first  entered  it  I  can  not  say.  As  they 
undoubtedly  came  in  large  numbers  their  work  has  been  rapid. 

I  sprayed  only  a  small  part  of  the  ranch  last  summer,  and  there  can  be  no  question 
but  that,  except  for  the  work  of  this  parasite,  our  place  would  be  teeming  with  the 
purple  scale,  whereas  I  have  yet  to  see  the  first  live  one,  and  our  fruit,  from  trees 
that  used  to  be  infested,  is  now  coming  off  the  tree  clean.  I  believe  this  ladybird  is 
also  eating  the  yellow  scale,  because  there  is  so  much  less  of  it  on  the  fruit,  but  of 
this  I  am  not  yet  sure. 

By  September  the  efficiency  of  the  purple  scale  parasite  should  be  thoroughly  estab- 
lished, for  if  any  live  eggs  are  left  they  must  hatch  before  that  time ;  yet  even  now  it 
seems  to  me  that  the  work  of  the  Scymnus  is  second  only  to  that  of  the  Vcdalin,  and, 
considering  the  difference  of  the  scales  and  the  fact  that  the  purple  is  so  heavily 
armored,  its  work  seems  even  more  remarkable. 

Seymnus  vagans.  This  is  one  of  the  smallest  of  the  ladybird 
family-,  but  not  one  of  the  least  important.  It  is  an  enemy  of  the  red 
spider  pest  which  is  very  general  all  over  the  world,  and  especially 
detrimental  to  almonds,  prunes,  and  citrus  trees.  The  long,  dry  seasons 
of  California  are  favorable  to  the  spread  of  this  pest,  which  flourishes 
under  arid  conditions,  and  which  has  been  especially  troublesome  here. 

This  little  ladybird  was  introduced  from  Australia  by  Mr.  George 
Compere  for  the  State  Board  of  Horticulture.  It  was  found  to  be  very 
effective  in  checking  the  spread  of  the  pest,  and  has  been  generally 
established  in  California. 


CALIFORNIA    STATE    HORTICULTURAL    COMMISSION. 


Rhizobius  debelis.  This  is  another  one  of  the  introduced  species  of 
ladybirds  which  we  OAve  to  Australia.  It  is  a  scale-feeder  and  has  been 
very  generally  distributed  in  the  State. 

Cryptolsemus  montrouzeri.  (Fig.  5.)  This  is  another  of  the  Austra- 
lian coccinellidae.  It  is  the  natural  enemy 
of  the  mealy  bug  (Pseudococcus  [Dactylo- 
pius] ) .  It  has  been  introduced  into  the 
Hawaiian  Islands,  where  this  pest  was  HO 
bad  in  the  coffee  plantations  as  to  almost 
threaten  the  total  destruction  of  the  crop, 
and  it  has  done  such  good  work  that  the 
pest  has  been  practically  cleaned  out.  Suc- 
cessful efforts  have  also  been  made  to  estab- 
lish it  in  the  coffee  plantations  of  Central 
America,  where  the  mealy  bug  has  also  ap- 
peared in  destructive  numbers. 


FIG.  .">.  Cryptolsemus  montrouzeri, 
enlarged. 


Hyperaspis  lateralis,  Mulsant.  This  is  one  of  our  native  ladybirds 
and  is  very  generally  distributed  over  the  State.  It  is  a  small,  black 
ladybird,  with  two  reddish-yellow  spots  on  the  elytra,  near  the  apex, 
two  spots  on  the  disc,  and  two  blotches  of  the  same  color  on  the  for- 
ward lateral  margins.  Forehead  and  edge  of  thorax  yellow.  Feeds  on 
pernicious  scale  in  the  adult  form.  Cypress  trees  (Cupressus  macro- 
carpa)  in  the  suburbs  of  San  Francisco  that  were  seriously  infested 
with  the  cypress  mealy  bug  (Pseudococcus  [Dactylopius]  ryani)  were 
cleared  of  the  pest  by  this  ladybird.  The  larvae  of  this  species  are 
covered  with  a  cottony  secretion  and  resemble  mealy  bugs. 

Exoehomus  pilati,  Mulsant.  (Fig.  6.)  This  is  another  of  our  very 
common  native  ladybirds.  It  resembles  in 
general  appearance  the  twice-stabbed  lady- 
bird (Chilocorus  [bivulnerus]  fraternus), 
but  is  much  larger.  It  also  differs  from  the 
latter  in  having  the  under  side  of  the  ex- 
tremity of  the  abdomen  black,  instead  of  red. 
The  larvae  resemble  the  twice-stabbed,  but 
are  larger  and  lighter-colored.  Both  the 
larva  and  beetle  feed  upon  young  black  scale,  but  they  do  not  increase 
very  rapidly. 

Chiloeopus  (bivulnerus)  fraternus  (Twice-stabbed  ladybird).  (Plate 
III,  Figs.  3,  3a.)  This  is  one  of  our  most  important  native  ladybirds. 
The  larvae  are  most  voracious,  and  destroy  great  numbers  of  young 
black,  pernicious,  and  other  scales.  The  young  are  long  and  covered 


FIG. 


BUG   VS.    BUG.  15 

with  dark  spines,  crossed  with  a  yellowish  band  near  the  middle. 
When  about  to  change,  into  the  pupa  or  chrysalis,  the  larva  selects  the 
under  side  of  the  large  branches,  where  it  attaches  itself  with  a  gummy 
substance  to  the  bark,  head  downward.  In  a  few  days  the  spiny,  larval 
skin  splits  longitudinally,  exposing  the  inclosed  chrysalis.  When  the 
beetle  issues  from  the  chrysalis  it  has  a  black  head,  with  white  wing- 
covers;  in  a  short  time  this  changes  to  a  shiny  black,  with  a  red  spot 
on  each  elytra.  In  this  stage  it  also  preys  upon  scale  insects. 

Coeeinella  sanguinea,  Linn.  (Blood-red  ladybird).  This  is  a  medium- 
sized  native  species,  found  very  generally  distributed  over  California. 
It  feeds  upon  aphids  and  young  scale  insects,  but  is  not  so  common  as 
some  of  the  other  species,  and  is  not,  therefore,  so  beneficial.  The 
beetle  is  of  a  solid  color,  varying  in  intensity  from  a  dull  red  to  a  bright 
scarlet. 

Coceinella  ealiforniea,  Mann.  This  species  is  a  very  common  one  in 
this  State,  and  the  beetles  are  sometimes  found  in  enormous  numbers. 
They  are  very  social  in  their  habits,  and  can  sometimes  be  found  in 
such  numbers  as  to  be  gathered  by  quarts.  They  are  larger  than  the 
sanguinea.  The  elytra  are  orange-red,  without  spots  or  markings; 
thorax  is  black,  with  a  light  spot  on  each  side.  They  feed  principally 
on  aphids.  Like  other  species  of  ladybirds,  the  larvge  do  the  most  good. 

Coecinella  abdominalis,  Say.  This  is  known  as  the  "ashy  gray 
ladybird,"  from  its  prevailing  color.  This  ladybird  is  hemispherical  in 
form,  ashy  gray  in  color;  with  seven  small  black  spots  on  the  thorax 
and  eight  on  each  wing-cover.  It  is  said  to  be  one  form  of  Coceinella 
oculata,  Say.  It  is  an  aphis-feeder,  and  where  it  exists  in  quantity  does 
good  work. 

Coceinella  oeulata,  Say  (Eyed  ladybird).  This,  while  it  is  supposed 
to  be  one  form  of  the  preceding,  does  not  resemble  it  in  any  manner,  in 
its  markings  or  general  appearance.  The  adult  insect  is  deep  black  in 
color,  with  two  distinct  orange-red  spots  on  the  wing-covers,  and  might 
easily  be  mistaken  for  Chilocorus  f  rat  emus.  There  is  a  distinct  differ- 
ence in  these  two  insects  in  the  markings  of  the  thorax,  the  oculata 
being  light  yellow  on  the  under  side  and  around  the  margin  of  the 
thorax.  Like  its  other  form,  abdominalis,  it  is  an  aphis-feeder,  and  a 
very  effective  one  where  it  is  found ;  but  in  this  form  it  is  not  a  common 
insect  in  this  State. 

Hippodamia  eonvergens,  Guer.  This  is  another  of  the  common 
ladybirds  of  California,  and  is  found  throughout  the  State  during  the 
summer  months  very  plentifully,  among  corn  and  other  vegetables. 
The  larvae  feed  upon  aphids  and  other  insects,  while  the  mature  insects 


EXPLANATION  OF  PLATE  III. 

Fig.  1.  Aspidiotophagus  citrinus.  Craw.     Enlarged, 

la.  Aspidiotophagus  citrinus.  Natural  size. 

2.  Aphelinus  fuscipennis,  Howard.    Enlarged. 

2a.  Aphelinus  fuscipennis.    Natural  size. 

.     3.  Chilocorus  bivulnerus;  "  twice-stabbed  ladybird. "    Natural  size. 

3a.  Chilocorus  bivulnerus.    Larva.    Natural  size. 

4.  San  Jose  scale  (Aspiodiotus  perniciosus,  Comstock).     Natural 

size.    On  pear  twig. 

5.  Yellow  scale    (Aspidiotus  citrinus,  Coquillett).     Natural  size. 

On  orange  leaf. 

6.  Rhizobius  (toowoombae)  lopantha.    Natural  size. 


CALIFORNIA  STATE  COMMISSION 
OF    HORTICULTURE. 


PLATE  1 


BUG    VS    BUG. 

THE    FOUR    SPECIES    OF  INSECTS    THAT    SUBDUED    TH 

'SAN  *JOSE  SCALE"  AND  "YELLOW  SCALE" 

IN  CALIFORNIA. 


BUG   Vfc.    BUG.  17 

also  feed  upon  aphids,  young  scale,  etc.  The  beetles  vary  somewhat  in 
color;  some  are  of  a  deep  red,  while  others  are  of  a  dull  brown,  the 
markings,  however,  being  uniform.  Sometimes  after  ripe  fruit  has  been 
punctured  by  birds  or  other  agencies,  the  beetles  of  this  species  will  be 
found  upon  it,  sipping  the  moisture,  and  on  this  account  they  have  been 
thought  sometimes  to  be  injurious.  They  are,  however,  among  the  most 
important  of  our  insect  friends. 

Hippodamia  ambigua,  Le  Conte.  (Figs.  7,  8,  9.)  This  is  a  very 
abundant  native  species.  The  adult  beetle  resembles  the  blood-red 
ladybird  somewhat,  but  is  narrower  in  proportion  to  its  length,  and 
flatter.  It  is  distributed  over  the  whole  State,  and  is  often  found  in 
great  numbers.  It  is  an  aphis  enemy,  and  does  excellent  work  on  the 
plum,  apple,  and  woolly  aphis.  During  the  later  fall  months  these 
insects  may  often  be  found  in  sheltered  places  in  great  masses,  in 
which  condition  they  hibernate  during  the  colder  months. 


PIG.  7.  Hippodamia  ainbigua.       FIG.  8.  Hippodamia  ambigua,       FIG.  9.  Hippodamia  ambigua, 
enlarged.  pupa.  larva. 

HYMENOPTERA. 

Seutellista  eyanea,  Motsch.  (Plate  IV,  Figs.  1,  la,  16,  Ic.)  This 
is  comparatively  a  new  introduction  into  our  State,  having  been  secured 
from  South  Africa,  where  it  was  found  to  be  a  very  effective  worker  on 
the  black^  scale  (Saisseta  oleae) .  In  the  short  time  it  has  been  estab- 
lished among  us,  it  has  done  most  remarkable  work,  and,  so  far,  promises 
to  be  as  efficient  a  check  for  the  black  scale  as  the  Vedalia  has  been  on 
the  cottony  cushion  scale.  Of  its  introduction,  Mr.  Craw  writes : 

It  was  not  until  Prof-.  Charles  P.  L/ounsbury,  Government  Entomologist  of  Cape 
Colony,  called  attention  to  the  Seutellista  eyanea  as  an  efficient  enemy  of  the  black 
scale  in  that  country,  that  its  true  value  was  recognized. 

Through  the  efforts  of  the  Hon.  S.  F.  Leib,  of  San  Jose,  and  Mr.  Ed.  M.  Ehrhorn, 
of  Mountain  View,  Senator  Perkins  appealed  to  the  United  States  Department  of 
Agriculture  to  use  its  good  offices  toward  securing  this  valuable  insect.  Several 
colonies  were  forwarded  to  Mr.  Ehrhorn,  but,  unfortunately,  without  any  practical 
results  from  either  sending.  On  October  1,  1901,  Professor  Lounsbury  wrote  me : 

"By  to-morrow's  boat  we  start  you  two  boxes  containing  cuttings  of  oleander 
bearing  parasitized  scale.  It  is  not  ideal  material  by  any  means,  and  this  is  not  the 
season  we  most  wish  to  send  in,  but  the  scale  and  its  parasites  are  both  so  scarce 
that  we  must  send  what  we  find  as  soon  as  we  find  it.  Most  of  the  scale  in  your 


18 


CALIFORNIA   STATE   HOBHCUI7TURAL    COMMISSION. 


vicinity  will  be  old  by  the  time  this  reaches  you.  but  I  am  in  hopes  that  you  may  be 
able  to  get  material  from  the  south  of  the  State  that  will  take  a  generation  of  the 
parasite.  Owing  to  the  probable  presence  of  secondary  parasites,  it  is,  of  course, 
inadvisable  to  send  the  original  material  to  any  orchardist  down  there." 

From  this  sending,  seventeen  perfect  insects  developed,  of  which  four  were  females. 
When  placed  in  a  breeding  case,  a  small  spider  that  was  hidden  in  a  rolled-up  leaf 
seized  and  killed  one  of  the  females,  leaving  us  but  three  from  which  to  colonize  the 
State. 

On  December  26,  1901,  I  examined  a  full-grown  black  scale  from  the  tree  in  the 
breeding  case,  and  found  a  small  maggot  of  the  $cutellista  cyanca,  about  twice  the 
size  of  a  black  scale  egg.  This  convinced  me  that  they  were  breeding,  so  no  further 
examination  was  made.  On  February  7,  1902,  the  parasites  began  to  issue  from  the 
scales.  During  the  warm  summer  months  we  found  that  the  Scutellista  passed 
through  all  its  metamorphoses  in  forty-seven  days. 

Colonies  have  been  sent  to  all  the  counties  of  the  State  where  black  scale  has  been 
troublesome.  From  personal  examination  and  from  material  sent  in,  it  is  evident 
that  the  parasites  have  obtained  a  good  start,  and  the  coming  season  will,  we  hope, 
see  them  thoroughly  disseminated. 


Description:  In  the  female,  the  antenna;  are  reddish-brown,  with 
the  ring  joints  and  hips  dark  and  more  spreading  than  in  the  male. 
The  antennae  of  the  male  are  black  from  the  ring  joints  to  and  including 


FIG.  10.    Tomocera  californica,  male,  greatly 
enlarged. 


FIG.  11.    Tomocera  californica,  female,  greatly 
enlarged. 


the  clubs,  with  the  scape  reddish-brown ;  the  legs  in  both  sexes  are  black, 
tarsi  reddish-brown,  and  claws  black;  the  scutellum  in  both  male  and 
female  is  very  large.  As  the  flies  are  small  and  very  active,  it  is  diffi- 
cult to  detect  them  on  the  tree  upon  which  they  may  be  placed,  and  the 
best  way  to  determine  if  they  are  established,  is  to  'remove  and  examine 
the  inside  of  the  full-grown  scales  about  forty  to  forty-five  days  after 
liberating  the  parasites.  The  larva  is  maggot-shaped  and  white,  this 
soon  changing  to  the  pupa,  which  is  black  just  before  changing  to  the 
perfect  fly. 

Tomoeera  (Dilophogaster)  ealiforniea,  Howard.  (Figs.  10, 11).  This 
is  one  of  our  native  internal  parasites.  In  has  been  one  of  the  most 
effective  checks  of  the  black  scale  in  the  State,  but  was  not  able  to  keep 


BUG   VS.    BUG.  19 

this  pest  wholly  under  control.     In  a  report  on  scale  insects  and  their 
parasites,  Professor  Comstock  says  of  this  insect  : 

This  is  one  of  the  most  interesting  parasites,  both  structurally  and  economically, 
which  we  have  discussed  in  this  paper.  It  lives  upon  the  destructive  black  scale,  and 
so  abundant  is  it  in  certain  regions  that  upon  more  than  one  tree  at  least  seventy-five 
per  cent  of  the  scales  appeared  to  be  parasitized.  In  no  locality  was  the  black  scale 
found  without  this  attendant  destroyer. 

The  female  parasite  pierces  the  body  of  the  female  bark-louse  and  deposits  probably 
but  a  single  egg.  At  all  events  but  a  single  parasitic  larva  has  ever  been  found  upon 
a  single  scale.  The  larva  of  the  parasite  feeds  upon  the  eggs  and  the  young  of  the 
Lecanium,  and,  also,  later  upon  the  mother  herself.  When  full  grown  it  is  about  0.15 
inch  long,  broad,  spindle-shaped,  somewhat  more  pointed  at  the  anterior  than  at  the 
posterior  end  of  the  body.  Its  color  is  clear  white,  the  contents  of  the  alimentary 
canal,  however,  often  showing  through  and  giving  it  a  blackish  tinge.  This  larva 
transforms  to  a  whitish  pupa,  which  soon  turns  black.  The  adult  parasite  makes 
its  exit  through  a  round  hole  which  it  cuts  in  the  back  of  the  scale. 

Hymeneyptus  erawii,  Aslimead.  This  is  an  Australian  insect,  and 
is  one  of  the  very  effective  internal  parasites  of  the  black  scale  in  that 
country.  It  was  introduced  into  California  by  Mr.  George  Compere, 
and  has  been  reported  as  doing  very  good  work  in  the  districts  where  it 
has  become  established. 

Aspidiotophagus  eitrinus,  Craw.  (Plate  III,  Figs.  1  ,  la.  See  Fig.  12.) 
The  internal  parasite  of  the  yel- 
low scale  (Chrysomphalus  [As- 
pidiotus]  eitrinus)  and  the  £>an 
Jose  scale  (Aspidiotus  pernici- 
os-us).  The  former  scale  was  at 
one  time  as  great  a  source  of 
trouble  to  the  orange-growers  of 
southern  California  as  the  red 
scale  (Chrysomphalus 


aurantU)  is  nOW.      It  fairly  FKJ.  12.    Aspidiotophagus  citrinus,  greatly 

enlarged. 

covered  the  citrus  trees,  reduced 

the  quantity  of  fruit,  and  destroyed  its  quality.  Every  effort  was  made 
by  artificial  means  to  resist  its  attacks,  but  these  were  unavailing. 
Finally  it  was  discovered  that  there  was  some  natural  check  at  work, 
and  investigation  discovered  this  little  internal  parasite.  Instructions 
were  at  once  given  to  the  orange-growers  to  stop  spraying  for  the  yellow 
scale  and  to  give  this  little  friend  a  chance  to  increase.  This  advice 
Avas  followed,  and  in  a  very  short  time  the  yellow  scale  disappeared 
from  that  section  and  it  has  not  since  been  regarded  as  a  pest,  although 
no  other  means  have  been  taken  to  check  it.  Mr.  Craw  has  bred  this 
parasite  from  yellow  scale  upon  imported  trees  from  Japan.  Mr.  Mar- 
latt  bred  it  in  numbers  from  San  Jose  scale  in  Japan.  It  is  also  one  of 
our  best  cheeks  for  the  same  scale  in  California. 


EXPLANATION  OF  PLATE  IV. 

Fig.  1.     Scutellista  cyanea.  Motsch.    Female :  enlarged, 
la.  Scutellista  cyanea.    Natural  size. 
Ib.  Scutellista  cyanea.    Larva;  natural  size. 

2.  Scutellista  cyanea.    Male;  enlarged. 

3.  Rhizobius  ventralis,  Blackburn.    Black  ladybird ;  enlarged. 
3a.  Rhizobius  ventralis.    Natural  size. 

3b.  Rhizobius  ventralis.    Larva;  enlarged. 

4.  "Black  Scale"  (Saisseta  [Lecanium]  oleae,  Bern).    On  orange 

twig. 

5.  "Black  Smut";  fungus,  existing  on  exudation  of  black  scale. 

6.  "Black  Scale,"  showing  exit  holes  of  Scutellista  cyanea. 


CALIFORNIA  STATE  COMMISSION 
OF   HORTICULTURE. 


PLATE   IV 


BUG    VS    BUG. 

THE    TRUE    PARASITE    AND    ENEMY 
OF  THE 

"BLACK.  SCALE. 


OF  THE  A 

(    UNIVERSITY   1 

OF 


BUG   VS.    BUG.  21 

Aphelinus  fuseipennis,  Howard.  (Plate  III,  Figs.  2,  2a.)  It  is  well 
within  the  memory  of  the  fruit-growers  of  California  when  the  San  Jose 
scale  was  the  most  terrible  of  our  pests.  It  antedated  the  appearance  of 
the  cottony  cushion  scale  and  attacked  nearly  all  of  our  deciduous  fruit 
trees.  For  some  time  it  seemed  as  though  the  fruit  industry  of  our  State 
was  doomed,  at  least  such  varieties  as  were  attacked  by  this  pest,  and 
orchardists  were  digging  out  and  destroying  their  trees  by  thousands  in 
order  to  stay  its  ravages.  Various  compounds  were  devised  to  fight  it ; 
among  them  the  now  celebrated  wash  of  salt,  sulphur,  and  lime  was  dis- 
covered as  most  effective.  This  wash  is  still  the  best  known  artificial 
remedy  for  San  Jose  and  kindred  scales  on  deciduous  trees;  but  it  is 
impossible  with  the  greatest  care  to  destroy  any  kind  of  pest  by  artificial 
means.  There  are  always  solitary  trees  which  will  be  neglected,  careless 
people  who  refuse  to  spray,  wild  shrubbery  out  of  reach  of  the  operators, 
and  all  of  these  become  sources  of  infection.  While  active  and  efficient 
work  was  being  done  by  artificial  means  against  this  pest,  it  was  discov- 
ered to  be  disappearing  in  sections  where  no  spraying  was  done,  and 
investigation  showed  that  one  of  our  native  parasites,  the  Aphelinus  fus- 
eipennis ,  had  adapted  its  taste  to  it  and  was  rapidly  getting  it  under. 
To-day,  wherever  the  San  Jose  scale  is  found  we  also  find  its  parasite, 
and  while  the  pest  has  not,  and  never  will  disappear,  it  is  entirely  con- 
trolled by  its  little  enemy  until  we  pay  no  further  attention  to  it. 
Spraying  is  still  carried  on,  however,  as  it  has  been  found  beneficial  to 
our  fruit  trees  in  killing  other  pests,  preventing  fungous  diseases, 
and  keeping  the  trees  healthy;  but  so  far  as  the  San  Jose  scale  is  con- 
cerned, there  is  no  further  need  of  artificial  remedies. 

This  same  parasite  is  generally  distributed  all  over  the  United  States 
and  is  undoubtedly  doing  good  work,  as  shown  in  our  quotation  from 
Prof.  W.  G.  Johnson  of  Maryland,  but  the  long  winters  and  compara- 
tively short  summers  there  may  check  its  spread.  In  the  mild  winters 
and  long  summers  of  California  it  probably  has  more  broods  than  there, 
and,  increasing  in  greater  quantity,  it  is  enabled  to  do  more  effective  work. 

Pteromalus  puparum.  This  is  a  very  common  enemy  of  the  cabbage 
butterfly  (Picris  rapae)  in  this  State,  and  undoubtedly  to  its  work  is 
due  the  fact  that  this  pest  is  not  more  common  than  it  is.  This  parasite 
has  a.  wide  range  and  is  found  over  the  greater  part  of  the  United  States. 
It  is  parasitic  upon  the  pupa  of  the  butterfly,  upon  which  it  lays  a 
number  of  its  eggs,  which,  hatching  out  in  its  unfortunate  victim,  puts 
an  end  to  its  career.  Prof.  F.  M.  Webster  in  "Insect  Life"  gives  an 
interesting  account  of  the  operations  of  this  insect,  as  follows : 

On  the  morning  of  August  9th,  we  observed  a  larva  of  I'ieris  protodice,  Boisd.,  in 
the  act  of  transformation  to  the  chrysalis.  Near  by,  and  very  evidently  watching  this 
transformation,  were  a  male  and  female  of  this  parasite.  The  trio  were  observed 
several  times  during  the  early  part  of  the  day,  the  parasites  always  on  guard,  as  it 


22  CALIFORNIA   STATE    HORTICULTURAL    COMMISSION. 

were,  although  the  females  several  times  were  observed  to  attempt  oviposition,  in 
ever.v  case,  however,  being  deterred  from  so  doing  by  the  jerking  of  the  larva,  now  in 
a  semi-pupal  state.  During  one  of  these  visits  the  male  was-  driven  away,  but  soon 
returned.  About  6  P.  M.,  the  last  observation  of  the  day,  the  transformation  of  the 
larva,  while  not  complete,  had  so  far  advanced  as  to  prevent  the  radical  movements 
which  had  characterized  its  struggles  during  the  forenoon,  and  the  female  was  busily 
engaged  in  her  work  of  oviposition,  the  male  still  present  as  a  spectator  (?i.  On 
the  morning  of  the  10th,  the  chrysalis,  now  fully  developed,  was  removed  and  placed 
in  a  glass  jar,  awaiting  further  developments.  On  the  morning  of  the  27th,  seventeen 
days  after,  the  adult  Ptcromalus  were  observed  issuing  from  the  chrysalis  in  great 
numbers.  After  all  had  emerged,  •  they  were  counted  and  found  to  number  us  males 
and  4  females.  The  same  parasite  had  been  reared  from  a  similar  chrysalis  on 
August  13th,  but  the  individuals  were  not  counted. 

Corny s  fusea,  Howard.  (Plate  II,  Figs.  3,  3a.)  This  is  one  of  the 
most  effective  of  the  scale  parasites  in  our  State.  Its  efforts  are  princi- 
pally directed  to  keeping  down  the  brown  apricot  scale  (Eulecanium 
[Lecanium]  armeniaciUH,  Craw) ,  and  wherever  it  has  become  thoroughly 
established  it  has  accomplished  this  object  in  very  good  style.  The 
brown  apricot  scale  has  been  one  of  the  most  serious  scale  pests  of  the 
State,  frequently  covering  the  twigs  of  apricot,  plum,  and  prune  trees 
with  an  almost  solid  incrustation,  destroying  the  vitality  of  the  trees, 
ruining  the  fruit,  and  doing  incalculable  damage.  By  means  of  this 
little  internal  parasite,  however,  we  are  enabled  to  keep  the  pest  well 
under  control,  and  whenever  there  is  an  outbreak  of  the  scale,  colonies 
of  the  parasite  are  sent  and  soon  become  established.  The  parasites  are 
small,  and  their  capture  and  shipment  require  great  care.  The  method 
in  which  this  is  done  is  by  noting  an  orchard  in  which  the  insects  are 
well  established  the  preceding  season.  From  this  orchard  large  quan- 
tities of  infested  twigs  are  secured  about  the  middle  of  May,  or  before 
the  parasites  begin  to  emerge  from  the  scale.  These  are  carefully 
trimmed  of  all  leaves  to  prevent  mildewing,  and  then  placed  in  square, 
wooden  receptacles  or  boxes,  as  shown  in  the  illustration  (Plate  VIII). 
These  boxes  are  bored  with  a  number  of  half -inch  holes  in  the  upper 
half  and  all  light  elsewhere  excluded.  Into  these  holes  small  vials  are 
fitted,  with  the  mouths  inward.  The  insects,  as  they  emerge  from  the 
scales,  seek  the  light  and  enter  the  vials  placed  to  receive  them,  and 
when  there  are  enough  in  any  one  to  form  a  colony  of  sufficient  size, 
usually  from  twenty-five  insects  up,  the  vial  is  removed,  stopped  with 
a  little  cotton  wool  to  prevent  their  escape  and  yet  admit  air,  another 
vial  is  set,  and  the  process  is  repeated.  The  vials  are  then  carefully 
packed  in  stiff  paper  tubes  (see  Plate  IX)  and  mailed  to  all  sections 
where  there  have  been  any  reports  of  outbreaks  of  the  scale.  In  this 
manner,  beneficial  insects  are  distributed  by  tens  of  thousands  all  over 
the  State  and  nature  is  aided  in  her  efforts  to  keep  our  insect  enemies 
within  proper  limits. 

Eneyrtus  flavus,  Howard.  (Plate  II,  Figs.  1,  la.)  This  is  one  of 
several  internal  parasites  of  the  soft  brown  scale  (Coccus  [Lecanium] 


BUG   VS.    BUG.  23 

hesperidum) .  This  scale  was  another  of  the  very  serious  pests  which  the 
orange-growers  of  California  had  to  contend  with  and  from  which  they 
have  been  relieved  by  insect  aids.  When  orange-growing  was  in  its 
infancy,  the  soft  brown  scale  obtained  a  foothold  in  the  orchards,  and 
without  any  check  soon  spread.  In  a  short  time  the  trees  were  covered 
with  it  and  were  suffering  greatly  from  its  depredations.  In  a  compara- 
tively short  time,  however,  it  began  to  disappear,  and  investigation 
showed  that  several  internal  parasites,  among  which  the  Encyrtus  flaws 
was  one  of  the  raoSt  important,  were  actively  at  work  upon  it.  and 
reducing  it  below  the  danger  limit. 

Coeeophagus  lecani.  (Plate  II,  Figs.  2,  2«.)  This  is  another  of  the 
internal  parasites  of  the  soft  brown  scale  (Coccus  hesperidum).  It  is 
found  in  several  of  the  Lecaniums,  but  its  best  work  in  this  State  has 
been  on  the  soft  brown  scale  of  the  orange,  which,  in  connection  with 
Encyrtus  flavus,  it  has  kept  below  the  danger  limit. 

Coeeophoetonus  sp.  This  is  an  internal  parasite  of  both  the  yellow 
and  red  scales,  and  while  it  has  not  done  as  extensive  work  as  some  of 
the  other  parasites  above  described,  it  is  none  the  less  an  important 
addition  to  our  list  of  friendly  insects. 

Eupelmus  mirabilis,  Walsh.  This  is  an  egg  parasite  of  the  katydid 
(Microcentrim  retinervis,  Scudder).  The  female  insect  lays  her  eggs 
within  those  of  the  katydid.  The  young  parasite  is  hatched  and  at 
once  proceeds  to  eat  the  eggs  of  the  host  insect.  The  Eupelmus  mirabilis 
has  been  an  invaluable  friend  to  the  orchardists  of  California  and 
especially  to  those  engaged  in  orange-growing,  where  at  one  time  the 
katydid  was  an  annoying  and  destructive  pest.  It  is  now  rather  a  rare 
insect  in  those  sections  where  it  was  once  so  common,  and  it  is  difficult 
to  find  its  eggs  without  observing  that  they  have  been  perforated  and 
destroyed  by  this  parasite. 

Besides  the  above-named  insects  which  are  common  in  California, 
and  to  which  without  doubt  we  owe  our  position  as  a  fruit-producing 
State,  there  are  a  number  of  others  of  greater  or  less  importance,  among 
them  a  species  of  Braconid,  parasitic  on  cutworms ;  Anastatus,  an  egg' 
parasite  of  the  tent  caterpillar,  and  another  parasite  of  the  tent  cater- 
pillar eggs.  There  is  also  a  Tachnid  fly  which  destroys  the  cabbage 
butterfly  by  laying  its  eggs  on  the  victim,  the  young  larva  hatched 
from  which  eats  up  the  caterpillar  and  destroys  it.  There  is  also  an 
internal  parasite  of  the  Eulecanium  (LecaniUm)  robinarum,  Douglas, 
and  a  species  of  Aphelinus  working  as  an  internal  parasite  of  the  aphis. 


24 


CALIFORNIA    STATE    HORTICULTURAL    COMMISSION. 


DIPTEROUS  INSECTS. 

In  the  great  family  of  dipterous  or  two-winged  flies,  we  find  very 
many  of  our  worst  pests ;  among  them  the  many  fruit  flies,  which  do  so 
much  damage  by  laying  their  eggs  in  the  ripening  fruit,  and  which 
hatching  out  into  a  mass  of  crawling  maggots  render  it  wholly  unfit  for 
use;  but  at  the  same  time  this  order  gives  us  very  many  of  our  best 
friends,  and  prominent  among  them  are  the  following : 


Lestopihqnus  ieerya.  (Plate 
I,  Figs.  5,  5<z;  also  Fig.  13.) 
This  is  an  exceedingly  small, 
two-winged  fly,  which  was 
found  at  work  on  the  cottony 
cushion  scale  at  Sidney,  N. 
•S.  W.,  by  Albert  Koebele. 
It  is  now  thoroughly  estab- 
lished all  over  California 
wherever  the  cottony  cushion 
scale  is  found,  and  has  proved 
itself  a  valuable  auxiliary  to 
th"1  Vcclalia  cardinalis  in  keep- 
ing that  pest  in  check. 


FIG.  13.    Lestophonus  ieerya,  enlarged. 


Celatoria  erawii,  Coquillett.  (Fig.  14.)  This  is  another  of  our 
beneficial  flies,  being  an  internal  parasite  of  the  well-known  twelve- 
spotted  squash  beetle,  so  common  in  fruit-growing  districts,  and  is  one 


Larva. 


•*&'<  it  *&&'*' 
^^Bl^^ 


Female,  enlarged. 

FIG.  14.    Celatoria  orauii,  Coq.uillett. 


Pupa. 


of  the  rare  instances  that  have  been  recorded  of  a  beetle  being  destroyed 
by  the  larvae  of  a  fly.  It  is  not  only  interesting  to  an  entomologist,  but  is 
of  great  assistance  to  the  horticulturist  in  reducing  the  numbers  of  such 
a  serious  pest.  Mr.  Craw  discovered  this  parasite  in  the  neighborhood 


BUG   VS.    BUG.  25 

of  Los  Angeles,  where  he  collected  a  large  number  of  the  beetles,  and 
found  that  fully  one  third  were  parasitized.  He  found  them  in  the 
larval  state  in  the  beetles  as  early  as  May  and  as  late  as  the  middle  of 
October.  The  May  brood  pupate  early  in  June  and  remain  in  this  con- 
dition about  two  weeks,  when  they  change  to  the  winged  form.  They 
are  numerous  in  July  and  August. 

Masicera  paehytyli,  Sk.  (Fig.  15.)  This  is  one  of  the  Tachnid  flies, 
the  whole  of  which  family  are  parasitic  on  other  insects.  They  are  of 
medium  size  generally,  and 
to  a  casual  observer  resemble 
our  common  house  flies.  The 
favorite  food  of  the  greater 
part  of  the  members  of  the 
family  are  the  caterpillars. 
The  female  lays  her  eggs  on 
the  soft  bodies  of  the  caterpil- 
lars and  the  young  grubs  de- 
vour their  host,  which  never 
attains  its  mature  state.  It  *' 

is  tO  this   family  that  the   re-  FIG   ]5     Masicera  pachytyH,  Sk. parasite  of 

duction  of  moths  and  butter-  the  locust, 

flies  below  the   danger  limit 

is  due.  The  one  of  which  we  give  an  illustration  in  Fig.  15  is  parasitic 
on  the  locust,  and  unquestionably  does  much  toward  keeping  this  terrible 
pest  in  check  in  Australia,  where  it  is  native.  This  is  one  of  the  intro- 
duced species  and  has  been  established  in  our  State.  Mr.  A.  H.  Bray 
gives  his  observations  on  this  insect,  as  follows : 

The  grub,  or  larva,  is  found  within  the  locust,  where  it  appears  to  live  upon  the 
adipose  tissues  of  the  victim,  avoiding  the  vital  parts  with  unfailing  instinct.  The 
grub  lives  indifferently  in  the  thoracic  region  or  the  abdomen  of  the  locust,  and 
frequently  three  or  four  may  be  found  in  a  single  grasshopper. 

The  grubs  leave  their  victims  when  they  are  full  grown,  usually  by  means  of  an 
opening  which  they  eat  in  tb.e  side  of  the  locust  at  the  point  where  the  abdomen  joins 
the  metathorax ;  but  they  do  not  invariably  make  their  exit  from' the  body  of  the 
unwilling  host  at  that  particular  place,  as  on  one  occasion  I  observed  two  grubs 
escaping  from  a  grasshopper  at  the  same  time — one  from  between  the  first  and 
second  abdominal  segments,  and  the  other  from  between  the  head  and  prothorax.  As 
soon  as  the  grub  makes  its  escape,  the  grasshopper,  which  has  gradually  grown  more 
and  more  feeble  as  the  inclosed  parasite  has  gained  in  size,  dies.  In  several  instances 
I  have  observed  that  the  grasshopper  died  before  its  enemy  succeeded  in  making- 
its  escape ;  and  in  one  case  a  larva  was  seen  vainly  struggling  to  free  itself  from 
between  the  metathorax  and  the  abdomen  of  a  dead  grasshopper,  where  it.  was 
firmly  held  by  the  contracting  remains  of  its  victim.  The  grub,  which  subsequently 
died  without  extricating  itself,  succeeded  in  freeing  more  than  half  its  body,  but  it 
was  firmly  held  by  the  tail. 

The  Sypphidas,  or  syrphus  flies  (Figs.  16,  17,  and  18),  are  another 
large  family  of  dipterous  insects,  many  of  which  are  beneficial  to  man. 


26  CALIFORNIA    STATE   HORTICULTURAL   COMMISSION. 

They  are  usually  very  conspicuous  from  size,  color,  and  markings,  and 
Tery  many  of  them  resemble  other  insects  and  may  be  mistaken  for 
bees,  .wasps,  etc.  They  are  often  seen  in  sunny  weather  poising  almost 
motionless  on  the  wing,  especially  over  flower-beds,  occasionally  darting 
on  their  prey.  The  larva  of  the  syrphus  flies  is  of  great  benefit  in 
•destroying  all  kinds  of  aphids.  It  is  quite  blind,  but  the  egg  from  which 
it  hatches  is  deposited  by  the  parent  fly  in  the  midst  of  a  colony  of 
plant  aphids,  where  it  gropes  about  and  obtains  an  abundance  of  food 
without  much  trouble.  The  larva  is  fleshy,  thick  and  blunt  behind,  and 
pointed  in  front.  Its  mouth  is  furnished  with  a  triple-pointed  dart, 
with  which  it  seizes  and  pierces  its  prey,  and,  elevating  it  as  shown  in 
the  figure,  deliberately  sucks  it  dry. 

MAGNIFIED  NATURALS.ZE 

MAGNIFIED  ,     NATURALS12E 


FI<;    Ifi.  FIG.  17.  FIG.  18. 

Larva  of  Syrphus  Fly.  Pupa  of  Syrphus  Fly.  Syrphus  Fly. 

This  is  but  a  partial  list  of  the  very  many  insect  friends  which  are 
doing'  so  much  for  California  horticulture,  and  which  it  has  been  the 
policy  of  the  State  Board  of  Horticulture  and  the  State  Horticultural 
Commissioner  to  foster  and  encourage  to  the  widest  extent,  and  at  the 
same  time  to  add  to  their  numbers  all  beneficial  insects  which  can  be 
secured  from  any  part  of  the  world.  To  this  end  correspondence  is  car- 
ried on  with  entomologists  in  different  parts  of  the  world,  while  agents 
of  this  department  are  dispatched  to  discover  and  introduce  beneficial 
species  wherever  they  can  be  found.  It  is  the  policy  of  this  State  to 
use  artificial  remedies  so  long  as  there  are  no  better  ones,  but  to  secure, 
introduce,  and  distribute  the  better  means,  and  these  consist  of  beneficial 
insects,  as  soon  as  possible.  In  California,  at  least,  this  plan  has  been 
found  a  very  effective  and  profitable  one,  for  of  all  the  many  insect 
pests  which  have  been  found  here,  and  they  are  as  numerous  as  any- 
where on  earth,  and  have  been  imported  from  all  parts  of  the  earth, 
there  are  not  now  more  than  two  or  three  really  serious  species,  and  all 
are  controlled  by  their  insect  checks,  either  native  or  introduced ;  and 
so  far  as  those  for  which  we  have  not  yet  found  an  effective  parasite  are 
concerned,  we  are  now  searching  for  one,  and*  in  view  of  our  past  suc- 
cess in  this  line,  will  undoubtedly  find  it. 


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